Veneer pressure bar



Sept. 25, 1962 H. F. ELFORD 3,055,406

VENEER PRESSURE BAR Filed Feb. 15, 1960 2 Sheets-Sheet 1 Harold EEJF INVENTO BY W4 /Mm Sept. 25, 1962 H. F. ELFORD VENEER PRESSURE BAR 2 Sheets-Sheet 2 Filed Feb. 15, 1960 Harold F Elford INVENTOR 1 nited States This invention relates to veneer lathe construction, and more particularly to the pressure mechanism used to bear against the periphery of a log and steady the same as the knife of the lathe moves into the log and cuts veneer therefrom.

In veneer lathes, it is customary to include such pressure mechanism to produce a degree of compression of the outer wood and prevent thick and thin cutting. Conventional pressure mechanisms have comprised either stationary press bars that slide against the log periphery as the log is revolved thereagainst, or an elongated, continuous roller suitably journaled at its ends that rolls against the log surface. The former type of construction is not suited for big lathes and tends to produce large resistances to turning of the lathe spindles, especially when high pressures are used. The latter type of construction has not been completely successful due to difficulties in mounting (which produced clearance difficulties), driving and lubricating the roller. A continuous rod construction has required constant maintenance and frequent replacement of parts.

According to this invention, it is contemplated that the pressure mechanism comprise an elongated mounting and plural roll segments set end to end in the mounting with a portion of their peripheries protruding outwardly therefrom and in position to engage a log surface. These roll segments constitute the roller means in the construction. Each of the roll segments has only a fraction of the length of the entire mounting. The roll segments are separated from each other by means of separator plates or spacers which are anchored in the mounting. Because of the relatively small mass of the segments, and because each is substantially independent of the other, it is not necessary or desirable to provide power-actuated means for rotating the roll segments. The log itself imparts suitable rotary movement to the roll segments. The roll segments are constrained for rotation in the mounting without the need of extensive bearing structure at the ends of the mechanism, as formerly was needed.

The use of plural, aligned roll segments has the particular advantage of permitting portions of the entire roller means to rotate at different speeds. Thus when a knot or other irregularity protruding from a log comes into contact with one of the roll segments, instead of tending to wedge momentarily against a single continuous roll thus to affect turning of the entire roll, this construction enables the knot to move over the roller means with those portions of the roller means to either side of the knot rotating freely. The segmented roll construction also takes care of slight tapers in logs, where the outer surfaces at the two ends of a log tend to move past the roller means at slightly different speeds.

In an embodiment of the invention, it is contemplated that novel means he provided for lubricating each of the roll segments. Thus an elongated groove portion is formed in the cavity mounting each roll segment, and this extends along the cavity the length of the roll segment. The groove during operation of the lathe is filled with lubricant, and as the roll segment rotates, it acts to transfer lubricant entirely around the bearing surface mounting the roll segment. This construction makes unnecessary the former practice of constantly feeding water over the pressure mechanism. It also enables longer continuous operation without shutdown time.

3,@55,40fi Patented Sept. 25, 1962 Another feature of the invention is the provision of novel means for introducing lubricant to the groove just discussed. Thus, in a preferred embodiment, the mounting for the roll segments takes the form of an elongated bar which is adapted to be supported on the usual support for the pressure mechanism of a lathe. This bar has extending out from one side thereof elongated pull studs that are used in positioning and securing the bar on the support. Each pull stud has an axial bore extending therethrough, such bore communicating with an additional bore formed in the mounting bar that communicates with one of the lubricating grooves. The construction enables a maintenance man rapidly to apply lubricant to the mechanism without disassembling the same.

Another object and feature is the provision of novel means for mounting the various roll segments so that each may readily be removed and replaced. The mounting for the rolls includes plural cap sections which are each detachably secured to the roll mounting bar, and have overlapping edges that partially define the elongated recess that mounts the rolls. These overlapping edges are adjustable toward and away from the base of the recess, when adjusting the clearance for the rolls. A single roll may be replaced by removing only one or two of the cap sections.

Other objects and advantages are attained by the invention which is described hereinbelow in conjunction with the accompanying drawings, wherein;

FIG. 1 is a section view of a veener lathe, showing the knife for the lathe and the location of the pressure mechanism which steadies and presses against the log during cutting of veneer therefrom;

FIG. 2 is a view taken along the line 2-2 in FIG. 1 illustrating in more detail the pressure mechanism of the invention;

FIG. 3 is a section view along the line 33 in FIG. 2 illustrating the lubricating system employed for lubricating the roll segments present; and

FIG. 4 is a section view along the line 4-4 in FIG. 2 showing the construction of a separator plate that spaces two roll segments from each other.

Referring now to the drawings for a description of a particular embodiment of the invention, and more particularly to FIG. 1, a veneer lathe generally indicated at 10 is shown having pedestals such as pedestal 12 at either end of the lathe. Movable in a horizontal direction to and fro between the pedestal and on suitable ways (not shown) is a knife structure indicated generally at 14 and pressure mechanism indicated generally at 16. The latter includes roller mechanism that normally contacts the periphery of a log and exerts compression thereon just before cutting veneer therefrom. The knife and mounting structure for the same is conventional, and comprises a frame 18 of A-shaped cross section mounting an elongated cutting knife 20. The latter is adjustable up and down on the A-frame by means of screws 22. The knife is clamped onto the frame by clamps such as clamp 24 having upper end portions bearing against one face of the knife. The top edge of the knife is beveled to provide the knife with a cutting edge. Pressure mechanism 16 includes a supporting structure 26 ordinarily mounted by means (not shown) permitting slight adjustment in the position of the structure relative to the cutting edge of knife 20.

Considering now specifically the construction of the pressure mechanism which forms the subject of this invention, and referring now to FIGS. 1, 2, and 3, extending along the nose end of structure 26 substantially the length of cutting knife 20 and adjacent the knife is an elongated mounting bar 28. The bar occupies a position substantially parallel to the cutting edge of the knife. Formed along the left side of the bar (the side that faces the knife) is an elongated cavity defined by a curving wall 30 that curves over an arc of a circle. Resting within this cavity are a series of cylindrical roll segments 32. The roll segments are relatively short compared to the length of knife 20 and bar 28. Thus with lathes having knives from six to twelve feet long, six to eight inch roll Segments may be employed (it should be understood, of course, that these dimensions are for purposes of illustration only). The roll segments are aligned with each other and set end to end so that the line of roll segments assume a position parallel to the cutting edge of the knife. Outer surface portions of the roll segments, indicated at 32a in FIG. 3, protrude outwardly beyond the side of the mounting bar that faces the knife. These protruding portions are the portions of the rolls that roll against the surface of a log as it is being processed. The roll segments have inner surface portions (indicated at 32b in FIG. 3) that slide against the concavely curved wall 3% During cutting of veneer, reaction forces produced by a log force the rolls inwardly against central portions of Wall 30 and thus the wall provides a bearing surface in the construction.

The roll segments are constrained to rotation within the cavity defined by wall 30 by a series of cap sections 36. These are arranged end to end along the top of bar 28, and are detachably secured to the bar. The cap sections have overlapping side edge portions 38 that protrude outwardly over the cavity defined by wall 30. These have inner surfaces that are curved as at 40 with a curvature roughly complementing the curvature of wall 30. The overlapping portions of the ca sections together with wall 30 of the cavity define an elongated, substantially cylindrical recess along the bar that opens to one side of the bar. Since the cap sections hold the rolls in place, these together with bar 28 constitute a mounting in the construction.

Each of the cap sections is provided with an elongated ridge 46 and flange 48 integral with the cap section and extending along the base thereof. The ridge and flange fit within channels 50, 52 provided in the bar. The ridge and flange when fitted in the channels lock the cap sections from lateral movement. Each is detachably secured to the bar by means of screws 56, one located at each end of the bar. For small adjustments of the overlapping side edges of the cap sections relative to the wall of cavity 30, a series of adjusting screws 58 is provided that have bottom ends bearing against surface 60. The overlapping edges are adjusted to provide suitable clearance for the roll segments, and to prevent chattering and looseness of the roll segments.

As best shown in FIGS. 2 and 4, separating adjacent roll segments is a separator plate or spacer 66. These have enlarged ends 68 that project outwardly into the recess defined by wall 30 and the overlapping side edges of the cap sections. The spacers also comprise anchoring portions 70 that are inserted into key Ways cut out of the mounting bar. These are thus held in place by the bar. By preventing the ends of the roll segments from contacting each other, spacers 60 prevent the various rol1 segments from spiraling and locking together. Thus each roll segment rotates independently of the others.

Extending along the bottom portion of wall 30 substantially parallel to the line of roll segments is an elongated groove 76. This groove thus has a portion that extends along the length of each roll segment. The groove functions as a holding means for storing lubricant for the rolls. The rolls pick up lubricant and distribute it over the wall 30. The groove is located downwardly from that portion of Wall 30 which takes the largest bearing stress during operation of the lathe. The spacers or divider plates have centrally located bores 78 and radially extending cutouts 80 formed therein. The cutouts and bores provide a passage for lubricant enabling it to work up from the grooves over the end surfaces of the various roll segments. In this way the roll segments are fully 4. lubricated, both at their ends and over their cylindrical surfaces.

The mounting bar 28 is brought securely into position against a wall 82 (see FIG. 3) of a seating ledge provided on supporting structure 26 by means of plural pull studs, indicated at 84. The pull studs or rods extend transversely of the bar and project out from the side opposite to that side mounting the roll segments. The pull studs have tapped ends 86 which are screwed into suitably threaded bores provided along the length of the mounting bar. The bodies of the studs extend through bores 88 formed in structure 26. Projecting ends of the studs are externally threaded, and nuts 92 are tightened onto these ends to tension the studs and in this way to pull the mounting bar snugly against wall 82. A pull rod is provided bar 28 at the location of each roll segment 32.

As a means for delivering lubricant to the lubricating groove portions already discussed, a conduit means is provided which extends through the pull studs and through the body of the mounting bar. Thus each pull stud has an elongated bore 96 extending axially through its center, and this communicates with one end of another bore 98 formed in the body of the mounting bar. The other end of bore 98 communicates with groove 76. Lubricant is ejected into the hollow interior of the studs by suitable dispensing mechanism fitted over the projecting ends of the studs. After filling with lubricant, bores 96 may be closed off as by fittings 100.

The construction described has a number of advantages. For one thing, friction in the lathe is considerably less than that resulting when a sliding press bar or means is employed. The roll segments of the pressure mechanism need not be power-driven, nor need extensive bearing structure be provided at opposite ends of the supporting structure 26 for constraining the rolls. The action of each roll is independent of the others, especially because of the spacers which separate the ends of adjacent rolls. The spacers do not add appreciably to rolling resistance, as provision is made for lubricating the ends of the rolls where they contact the spacers.

A supply of lubricant is provided the roll segments through the hollowed-out pull studs and bores described. The groove along the base of wall 30 holds a supply of lubricant suflicient to let the machine operate continuously for a considerable period of time.

In the event it is desired to replace any of the roll segments, the entire cap assembly need not be removed but instead only isolated cap sections. After removal, a particular segment is easily taken out of the assembly. To remount a roll segment, the removed cap sections are replaced, and by adjustment of screws 56, 58, proper clearance is provided the newly inserted roll segment.

It is claimed and desired to secure by Letters Patent:

1. For a veneer lathe having a frame and elongated cutting knife means mounted thereon for cutting veneer from a log, pressure mechanism adapted to be mounted on the lathe substantially parallel to the knife means for bearing against and thus pressing the exterior of a log during cutting of veneer therefrom, said pressure mechanism comprising an elongated mounting bar means, an elongated concave cavity formed along one side of the bar means, plural cap sections set end to end on said bar means with side edge portions extending over said cavity and partially closing it off, means detachably securing the latter cap sections to said bar means, inner surface portions of said cap sections and the wall defining said cavity together defining an elongated recess means of substantially cylindrical cross section and open along said one side of the bar means, plural cylindrical roll members constrained to rotary movement Within said recess means and set end to end along a line within said recess means, spacer plates between said roll members fitted into said recess means and extending transversely thereof and anchored against lateral movement in said bar means, an elongated groove portion for each of said roll members formed along the length of that portion of the recess means containing the roll members, and lubricant delivery conduit means extending through the bar means connecting with the groove portion provided for a roll member.

2. The pressure mechanism of claim 1 wherein the bar means is provided with adjusting studs set transversely of the bar means and projecting out from the side opposite to said one side, and wherein the lubricant delivery conduit means comprises a bore extending axially through a stud and another bore connecting an end of the firstmentioned bore and said groove portion.

3. Pressure mechanism for a veneer lathe adapted to be mounted adjacent and substantially parallel to the knife of the lathe and for bearing against and thus pressing the exterior of a log during cutting of veneer therefrom, said pressure mechanism comprising an elongated mounting bar adapted to be set with one side thereof facing the knife of the lathe, elongated recess means provided along one side of the mounting bar of substantially cylindrical cross section and opened up along its length to said one side of the bar, plural rolls constrained to rotary movement within said recess means and set end to end therealong, and separator plates anchored in said mounting bar arranged transversely of the rolls, at least one between each roll, and spacing the ends of the rolls from each other.

4. In combination with a veneer lathe having cutting knife means for cutting veneer from a log, pressure mechanism engaging and thus pressing against the external surface of a log during cutting of the veneer therefrom, said pressure mechanism comprising an elongated mount ing bar positioned substantially parallel to the knife means and having one side facing the knife means, an elongated, concavely curved wall defining a concave cavity formed along said one side of the bar and extending substantially along the length thereof, plural cap sections set end to end with side edges thereof overlapping said cavity, said overlapping edges of the cap sections together with the wall defining said cavity defining an elongated recess means along said one side, means detachably securing the cap sections to said bar, means for adjusting the position of the overlapping edges of the cap sections relative to the wall defining said cavity, plural separator plates anchored in said bar with portions dividing said elongated recess means into compartments, and a cylindrical roll mounted within each of the said compartments and constrained to rotary movement therein, the roll having surface portions protruding outwardly of said one side of the bar.

5. The construction of claim 4 which further comprises a lubricating groove portion provided for each roll and formed in the concavely curved Wall defining the cavity, and conduit means for delivering lubricant to the groove portion.

6. The device of claim 5 wherein said conduit means comprises an adjusting stud secured to the bar extending transversely of the bar and outwardly from the side of the bar opposite said one side, a bore extending axially through said stud, and another bore formed in the bar connecting the bore of the stud with the groove portion.

7. For a veneer lathe having elongated cutting knife means for cutting veneer, pressure mechanism for engaging the surface of a log during cutting of veneer therefrom, said pressure mechanism comprising an elongated bar adapted to be mounted on a lathe substantially parallel to the knife means and with one side thereof facing the knife means, an elongated, concavely curved cavity formed along one side of the bar, plural cap sections set end to end with side edge portions extending over said cavity and partially closing it oif, means detachably securing the latter sections to the bar, inner surface portions of said cap sections and said cavity together defining an elongated recess of substantially cylindrical cross section and opened along said one side of the bar, plural cylindrical roll members set end to end constrained to rotary movement within said recess, and separator plates separating the ends of the roll members, at least one between each adjacent set of ends of roll members, said separator plates being anchored in said bar.

References Cited in the file of this patent UNITED STATES PATENTS 1,016,737 Caulston Feb. 6, 1912 1,625,881 Buss et a1 Apr. 26, 1927 1,641,452 Osgood Sept. 6, 1927 1,804,704 Osgood May 12, 1931 

